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An extract of leaves and stems of Peperomia villipetiola has been found to contain myristicin (3-methoxy-4,5-methylenedioxy-allylbenzene) and seven chromenes, whose structures are methyl 5-hydroxy-7-methyl-2,2-dimethyl-2H-1-chromene-6-carboxylate (1), methyl 5-methoxy-7-methyl-2,2-dimethyl-2H-1-chromene-8-carboxylate (2), methyl 7-hydroxy-5-methyl-2,2-dimethyl-2H-1-chromene-6-carboxylate (3), methyl 7-methoxy-5-methyl-2,2-dimethyl-2H-1-chromene-6-carboxylate (4), 5-methanol-7-hydroxy-2,2-dimethyl-2H-1-chromene-6-carboxylic acid (5), 5-methanol-7-methoxy-2,2-dimethyl-2H-1-chromene-6-carboxylic acid (6), and methyl 5-acetoxymethanol-7-hydroxy-2,2-dimethyl-2H-1-chromene-6-carboxylate (7). A biosynthetic rationale for 1-7 suggests that orsellinic acid may be a common intermediate. The anti-fungal activities of the chromenes were measured bioautographically against Cladosporium cladosporioides and Cladosporium sphaerospermum: compounds 6 and 7 were found to be the most active.

Antifungal activity guided fractionation of the n-butanol extract from the methanol extract of the leaves of Artocarpus nobilis furnished 2',4',4-trihydroxy-3'-geranylchalcone (1), 2 ',4',4-trihydroxy-3'-[6-hydroxy-3,7-dimethyl-2(E),7-octadienyl]chalcone (2), 2',4',4-trihydroxy-3'-[2-hydroxy-7-methyl-3-methylene-6-octaenyl]chalcone (3), 2',3,4,4'-tetrahydroxy-3'-geranylchalcone (4), 2',3,4,4'-tetrahydroxy-3'-[6-hydroxy-3,7-dimethyl-2(E),7-octadienyl]chalcone (5). The chalcones 3 and 5 are new natural products whereas 1 and 2 are reported first time from the family Moraceae. All these compounds showed good fungicidal activity against Cladosporium cladosporioides and high radical scavenging activity towards the 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical in TLC bio-autography method.

A new acylated form of a phloroglucinol with significant antimicrobial properties was isolated by bioactivity guided fractionation from Helichrysum caespititium (Asteraceae). The structure elucidation, and conformation of the new phloroglucinol, 2-methyl-4-[2',4',6'-trihydroxy-3'-(2-methylpropanoyl) phenyl]but-2-enyl acetate, was established by high field NMR spectroscopic and MS data. The compound inhibited growth of Bacillus cereus, B. pumilus, B. subtilis and Micrococcus kristinae at the very low concentration of 0.5 microg/ml and Staphylococcus aureus at 5.0 microg/ml. Six fungi tested were similarly inhibited at low MICs, Aspergillus flavus and A. niger (1.0 microg/ml), Cladosporium chladosporioides (5 microg/ml), C. cucumerinum and C. sphaerospermum (0.5 microg/ml) and Phylophthora capsici at 1.0 microg/ml.

Chromatographic fractionation of the dichloromethane extract from roots of Virolasurinamensis yielded two new natural products, 3- epi -juruenolide C and2′-hydroxy-7,4′-dimethoxyisoflavone, as well as various known steroids, lignans, isoflavones,flavonoids and diarylpropanes. Of these, a,2′-dihydroxy-4,4′-dimethoxydihydrochalcone,biochanin A and 2′-hydroxy-7,4′-dimethoxyisoflavone displayed antifungal activity against Cladosporium cladosporioides at a minimum amount of 5 mg, whereas 7-hydroxyflavanone and7-hydroxy-4′-methoxyisoflavone exhibited an antifungal activity 10-fold higher than the positivecontrol Nystatin.

6,8-Dimethoxy-3-(2'-oxo-propyl)-coumarin (1) and 2,4-dihydroxy-6-[(1'E,3'E)-penta-1',3'-dienyl]-benzaldehyde (2), in addition to the known compound periconicin B (3), were isolated from the ethyl acetate extract of Periconia atropurpurea, an endophytic fungus obtained from the leaves of Xylopia aromatica, a native plant of the Brazilian Cerrado. Their chemical structures were assigned based on analyses of MS, 1D and 2D-NMR spectroscopic experiments. Biological analyses were performed using two mammalian cell lines, human cervix carcinoma (HeLa) and Chinese hamster ovary (CHO). The results showed that compound 1 had no effect when compared to the control group, which was treated with the vehicle (DMSO). Compound 2 was able to induce a slight increase in cell proliferation of HeLa (37% of increase) and CHO (38% of increase) cell lines. Analysis of compound 3 showed that it has potent cytotoxic activity against both cell lines, with an IC50 of 8.0 microM. Biological analyses using the phytopathogenic fungi Cladosporium sphaerospermum and C. cladosporioides revealed that also 2 showed potent antifungal activity compared to nystatin.

Five cadinane sesquiterpenes derivatives were isolated by bioassay-guided fractionation from Phomopis cassiae, an endophytic fungus isolated from Cassia spectabilis. The structures of the two diastereoisomeric 3,9,12-trihydroxycalamenenes (1, 2); 3,12-dihydroxycalamenene (3); 3,12-dihydroxycadalene (4) and 3,11,12-trihydroxycadalene (5) were established on the basis of analyses of 1D and 2D NMR and HRTOFMS experiments. Antifungal activity of the isolates was evaluated against Cladosporium sphaerospermum and Cladosporium cladosporioides, revealing 5 as the most active compound.

An isolate of Curvularia sp. was obtained from the leaves of Ocotea corymbosa, a native plant of the Brazilian Cerrado. The ethyl acetate extract from culture of this fungus afforded two benzopyran derivatives: (2'S)-2-(propan-2'-ol)-5-hydroxy-benzopyran-4-one (2) and 2,3-dihydro-2-methyl-benzopyran-4,5-diol (4); and two known benzopyrans: 2-methyl-5-methoxy-benzopyran-4-one (1) and (2R)-2,3-dihydro-2-methyl-5-methoxy-benzopyran-4-one (3). The structures of 2 and 4 were established on the basis of comprehensive spectroscopic analysis, mainly using 1D and 2D NMR experiments. The benzopyrans 1 and 2 showed weak in vitro antifungal activity against Cladosporium sphaerospermum and C. cladosporioides. Analyses of the biological activities were also carried out on HeLa (human cervix tumor) and CHO (Chinese hamster ovary) cells, aiming to evaluate their potential effects on mammalian cell line proliferation. Results from both cell lines indicated that compound 2 was able to induce cell proliferation: 70% on HeLa cells and 25% on CHO cells.

Bioactivity-guided fractionation of the EtOAc extract from leaves of Piper crassinervium yielded three prenylated hydroquinones together with two known flavanones naringenin and sakuranetin. Their structures were determined by means of spectroscopic analysis (NMR, IR, UV and MS) including two-dimensional NMR spectroscopy experiments (1H–1H COSY, HMQC, HMBC and NOESY). The antifungal activity was determined by direct bioautography against Cladosporium cladosporioides and C. sphaerospermum.

Bioactivity-directed fractionation of the CH2Cl2/MeOH (2:1, v/v) extract of the roots of Petiveria alliacea, using mutant yeast strains of Saccharomyces cerevisiae and fungi Cladosporium cladosporioides and C. sphaerospermum led to the isolation of dipropyl disulphide (1), dibenzyl sulphide (2), dibenzyl disulphide (3), dibenzyl trisulphide (4), dibenzyl tetrasulphide (5), benzylhydroxymethyl sulphide (6) and di(benzyltrithio) methane (7). Of these, 5–7 are new compounds and this is the first report of the natural occurrence of 2 and 3.

2′,3-Dihydroxy-5-methoxybibenzyl (Batatasin IV), its demethyl derivative and 3,5-dihydroxybibenzyl (dihydropinosylvin) were isolated only from flesh of Dioscorea rotundata infected with Botryodiplodia theobromae and may therefore be considered phytoalexins. These compounds were found to be antifungal using bioassays with Cladosporium cladosporioides, Botryodiplodia theobromae, Aspergillus niger and Penicillium schlerotgenum . Dihydro-pinosylvinin also exhibited strong antibacterial activity against Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli .

The roots of Croton lacciferus afrorded a novel ent -kauranoid and three other ent -kauranoid alcohols, one of which is a new natural product, together with 2,6-dimethoxybenzoquinone. The benzoquinone displayed antifungal activity against Cladosporium cladosporioides